Coal washer box



" May 19,1931.

B. NORTON 1,806,493

COAL WASHER BOX Filed March 29, 1928 2 Sheets-Sheet l v 21 gr 1; IV o a 1 J? V 15 W e/v70? B. N o r to n y 1931. B. NORTON 1,806,493

COAL WASHER BOX Filed March 29, 1928 2 Sheets-Sheet 2 WVf/VTOI? 13. Norton Patented May 19, 1931 UNITED STATES PATENT OFFICE IBERTRAM NORTON, F CLAVERLEY, ENGLAND, ASSIGNOR T0 NORTONS (TIVIDALE) LIMITED, TIITON, ENGLAND, A BRITISH COMPANY COAL WASHER BOX Application filed March 29, 1928, Serial No. 265,734, and in Great Britain April 26, 1927.

This invention relates to washer boxes for coal and the like of. the type in which the material to be washed is caused to travel over perforated plating through which water is 5 caused to rise and fall in pulsations under the action of air underpressure, or by any equivalent means. In washer boxes of this type the shale is separated from the coal owing to difference in density, and during normal working a bed of shale is allowed to form on the perforated plating.

Generally in such washer boXes the shale is discharged from the washing bed through an aperture controlled by a gate moving in guides, with the result that the weight of the coal and shale forces the gate against the guides so that considerable frictional resistance has to be overcomebefore it can be moved. It is the principal object of the present invention to provide an improved form of gate which shall be very easily moved and-shall be particularly suitable for automatic control. It is a further object of the present invention to ensure that any risk of incomplete closing of the gate shall be elim: inated so that positive action can be ensured when the box is worked automatically. Another object of the present invention is to control the operation of the improved gate by means of a float device in accordance with the depth of the shale layer, so that when the layer builds up above a predetermined height the gate shall be opened and the shale allowed to flow out, but on the layer sinking below a predetermined height the gate will close again.

Yet a further object of the invention is to provide an improved form of float, and to mount it so that it will always remain truly vertical, and further to connect the float to control the gate through a compressed air relay -mechanism. Such a relay mechanism is particularly suitable for use in coal washer boxes of this type, since the pulsations of the water are generally produced by means of compressed air which is consequently easily available. Owing to the pulsations of the water, the float will always rise and fall slightly even though the depth of the shale remains constant. This would produce corresponding variations in the position of the control valve of the compressed air relay mechanism which would be most undesirable, and accordingly another object of the invention is to allow the float to move with the pulsations of the water without actuating the relay mechanism.

lVith these and other objects in view, according to the present invention, the gate controlling the discharge of the shale is mounted outside the limits of the washing bed, and conveniently may be pivotally mounted so as to swing outside the forward edge of a shelf projecting from beneath the aperture in the walls surrounding the washing bed through which the shale flows out. This gate may then be arranged to lie beneath the shelf to allow the shale free discharge, but to swing upwards and intersect the outflowing stream of shale when it is desired to stop the shale discharge. It is found that with such a gate the discharge of the shale is stopped entirely when the leading edge of the gate reaches the level of the top of the aperture irrespective of the height of the top sur- 7. face of the working bed above the aperture. Such a gate is very easily moved since it is not forced by the weight of the shale and coal against any guides, and so it is particularly suitable for automatic control through a relay mechanism by means of a float. Conveniently a lost motion device is inserted between the float and the relay mechanism so as to allow the float to respond to the pulsations of the water without actuating the relay mechanism. In order to maintain this float truly vertical it is preferably carried by means of a parallel motion mechanism. By this means it is effectually prevented from jamming orsticking. The improved float may be made as a hollow body into which weighting material can be filled, so that it will sink through the coal layer but rest upon the shale layer, and it may conveniently be made of elongated cross-section or may be stream-lined so that the washing water and material will pass it easily.

The invention will be more clearly understood from the following description of one form of box, constructed in accordance there- 100 the handle 11 so that as the piston 28 moves to the left the handle 11 is forced over to the left also, thus swinging the gate 7 downwards beneath the shelf 6. The shale then flows freely out through the aperture 4 until the float 12 sinks, pulling the rod 21 and piston valve 23 to the right, and thus closing the port 26. Then the piston valve 23 moves further to the right it will uncover the port 26 so that the air passes out from the cylinder 29 through this port, through the hollow centre of the piston valve 23 and so out to the atmosphere through the end of the casing 22. The gate 7 will then automatically swing upwards because the handle 11 is connected by 7 means of a rope 33 and pulleys 34 to a restoring weight.

It will be realized that the adjustment of the float 12 is comparatively delicate, and it is always desirable, therefore, to operate the gate 7 through a relay mechanism such as that shown. It is further found desirable to make the float 12 of elongated cross-section shown, so that the material and washing water flowing through the box 1 will pass it easily, and further for the sake of greater accuracy the actual linkage carrying the float is balanced by a weight 35 rigidly con nected to the transverse rod 19.

Figure 4 shows a part of a washer box having a modified form of shale outlet gate. In this case the gate 7 still has its closure surface formed as a sector of a cylinder, but the axis 9 about which the gate is pivoted is spaced well away from the outlet aperture 4 so that the surface of the gate 7 lies between the axis 9 and the aperture 4. In this case the gate is shown in its closed position in full lines, and swings, so as nearly to touch the forward edge of the perforated shelf 6, into the position shown in dotted lines in which the outflowing shale flows over the closure surface of the gate and then drops downwards.

By reference to Figure 5, wherein is shown diagrammatically a means for admitting compressed air to cause pulsations of water in the washer box, air under pressure from a suitable source passes from line 40 through port 43 of a valve element 42 arranged in a valve bonnet 41, and thence to a compartment formed by wall 46 extending below the normal liquid level in box 1, thereby causing a surge or pulsation in a known manner. Upon rotation of the valve element 42 as by a suitably driven cable 48 and pulley 47, air in the aforesaid compartment may be Vented upon ports 44, 45 coming in registry to cause a return pulsation or surge. Equivalent means for causing such pulsations or surges may of course be substituted.

Although one construction of washer box according to the invention has been described in detail, the invention is not, of course, limited to this.

The shale outlet gates are generally provided at both ends of the washer box so that it will generally be desirable to provide separate floats for the shale outlet gates at the inflow and outflow ends because the rates of discharge will be different.

Having thus described my invention what I claim as new, and desire to secure by Letters Patent, is

1. A coal washer box having an end discharge aperture, a. shelf projecting from the lower edge of the aperture and away from the box, a gate supported on and swingable about an axis outside the box and spaced from the outer edge of the shelf, mechanism responsive to variations in the shale level in the box to swing the gate to a position below the upper surface level of the shelf and to a position above said shelf, the gate being shaped to maintain substantial contact with the outer edge of the shelf in all positions.

, 2. A coal washer box having an end dischargeaperture, a shelf projecting from the lower edge of the aperture and away from the box, a gate supported on and swingable about an axis outside the box and spaced from the outer edge of the shelf, mechanism responsive to variations in the shale level in the box to swing the gate to a position below the upper surface level of the shelf and to a position above said shelf, the gate being in the form of a sector of a cylinder to maintain substantial contact with the outer edge of the shelf during such swinging movement.

3. A coal washer box having an end discharge aperture, a shelf projecting from the lower edge of the aperture and away from the box, a gate supported on and swingable about an axis outside the box and spaced from the outer edge of the shelf, mechanism responsive to variations in the shale level in the box to swing the gate from a normal position nearly completely below said shelf and to a position above said shelf, the gate being in the form of a sector of a cylinder and maintaining substantial contact with the outer edge of the shelf during such swinging movement. a

4. In a coal washer box comprising a receptacle in which the material under treatment is maintained as a washing bed, said receptacle being formed with an aperture for the discharge of shale from said washing bed, the combination of a shelf projecting from beneath said aperture and beyond the end of the receptacle, a gate extending in an upwardly inclined position, pivoted remotely from the shelf and bodily movable along an are located outside the forward edge of the shelf and which extends above and below the shelf, and means responsive to variations in depth of the shale layer to operate said gate.

5. In a washer box for coal in which the material under treatment is maintained as 7 through said perforated bottom, a: movable a washing bed, in combination, a Y receptacle for said washing bed, one of the wallsof said receptacleibeing formed with an outlet aperture for the shale, a, shelf projecting from; beneath said aperture, a perforated; bottom: to said receptacle,means for admitting coinpnessed airto cause; pulsations; of water gate normally disposed belowsaid shelf but capable ofmo-ving upwards through the outflowingshale to co-operate with; the forward:

edge of said shelf, afloat soweighted as. to

sink through the coal layer but to float upon the-shale layer, a compressed air relay mechanism formedwith air passages and operatively connected to move said gate and a, Valve member forming part of said relay mechanism and actuated upon therise and fall of said float to control said air passage.

x 6;:-In a washer box for coal in which; the

material under treatment is. maintained as a, washingbed, in combinatioma recep cle 1501' 7 said washing bed, one of the walls of said;

receptacle being formed with; an outlet aperture for the shale, a: shelf projecting from beneath, said a-perture,,a1 perforated: bottom to said receptacle, means for a mitting com pressed? air to cause pulsations of Water through: said perforated bottom, a: movable. gate normally disposed below said shelf but capable of moving upwards through-the outflowingshale to co-operate with theforward edge of said shelf, a float-so weighted as to V i V sinkthrongh the coal layer but, to float upon theshale layer, acompressedair relay meeh-- anism= comprising a casingjformed; with passages, a piston; valve sliding in; said joasin and co-operating with. said passages, said: valve being operatively connected with; said float so as to. be actuated in accordance with therise and fall thereof, acylinder' commnnie eating with said casing by one of said pas, sages,-and apistonsliding-in said cylinder and operatively connected to opensaid'gate;

'Z. In a coal washer box, in which the materialfunder treatment is maintained as a washing-bed,.a receptacle for said washing bed, a member rigid with said receptacle, a

Ifloat so Weighted as to sink through the coal layer but tofloat upon the shale layer of saidwashi-ng'bed', and parallel motion, linlfreon.

nections between said member and said float, 7

said link connections being'so disposed as tom'aintainsaid float'vertical-,,

In witness'whereof I hereunto: subscribe my name this 16th ,dayof MarchArD, I928.

Y BERTRAM NORIQN. 

